Quantifying Biomass Burning Contributions to Winter Air Pollution in Interior Alaska

SARAVANAN KANAGARATNAM, Raghu Betha, Venky Shankar, Texas Tech University

     Abstract Number: 391
     Working Group: Source Apportionment

Abstract
Air pollution from carbonaceous aerosols (CA) is a serious concern in subarctic regions of Interior Alaska due to its far-reaching implications for the environment, climate, and public health. The city of North Pole within the Fairbanks North Star Borough (FNSB) in Interior Alaska experiences severe winter air pollution with average daily PM2.5 concentrations reaching up to 73 μg/m3. This led the EPA to designate the FNSB as a “serious non-attainment” zone in 2017 due to air quality concerns. Wood and other biomass burning is a primary source of residential heating in the region and is the main source of CA. However, there are no estimates of the source contributions to CA during winter. This research analyzed data from two one-month field campaigns using an aethalometer and total carbon analyzer to estimate the contributions of different sources to Black Carbon (BC) and organic carbon (OC). Existing methods for source apportionment require extensive data (often year-long data) and knowledge of specific source markers. This study proposed a new approach that doesn’t need such extensive data or information on source markers, allowing for source estimates with smaller datasets. The results from the model show that the site-specific Absorption Ångstörm Exponent (α) values for biomass burning (α_bb), and fossil fuels (α_ff) were 1.87 and 0.93, respectively. It was estimated that biomass burning contributed 52 % to the BC (BC_bb) and 86%, to OC (OC_bb), while the fossil fuel contributed 48% to BC (BC_ff) and 14% to OC (OC_ff). These findings highlight the significant role of residential wood burning in winter air pollution in the North Pole. Biomass burning contributed over 80% of the OC and over half of the BC in the air. This information can be crucial for developing effective regulations to address air quality issues in the region.